This open-label study will assess the efficacy and safety of Avastin (bevacizumab) plus Xeloda (capecitabine) in combination with standard technique radiotherapy of the pelvic region in the neo-adjuvant setting in patients with locally advanced primary rectal cancer. Patients will receive 4 courses of Avastin at a dose of 5 mg/kg intravenously (iv) every 2 weeks and for 38 days Xeloda at dose of 825 mg/kg twice daily orally, plus radiation therapy. After surgery, adjuvant treatment with 5-fluorouracil/leucovorin and, at the discretion of the investigator, with Avastin 5 mg/kg iv every 2 weeks for at least 6 months will be given.